But the river of money has run dry now after more than a dozen different drug traffickers told the terrorists they were not prepared to hand over any more cash.
This has led the terrorists to compile a hit list that includes 13 Dublin-based criminals, as exclusively revealed in the Herald yesterday.
A dissident source said: "Since Ryan was murdered in September, there has been virtually no money going to Belfast from Dublin. The murder itself seems to have made drugs gangs think that they are stronger than the IRA.
"When Alan was at his peak -- taxing the scumbags -- five-figure sums of hard cash were being brought up every month. This has dried up now."
The Real IRA in Dublin is on a knife edge as a major cleansing operation continues.
Major dissident Republicans from the North are now based in south Dublin and are vowing to cleanse the mob of the "scumbag rabble that were recruited by Alan Ryan".
In particular, four senior members of the terror gang are now based in south Dublin and have been conducting "internal interrogations". A key element of the operation being led by Northern figures will see the Real IRA's core activities shifted from north Dublin to the south inner city, the Herald has learned.
"The south inner city will become the new stronghold of the IRA. The work in achieving this has already begun."
The organisation's Dublin-based members have been ordered to abandon their extortion activities in north Dublin after it was established that they were being "closely monitored" by detectives, they claim.
But in reality many sources believe that the north Dublin crime mob who organised Ryan's murder actually has more firepower than the RIRA.